Thread cutter for sewing machines or the like



Oct. 18, 1932. 0. w. HDOUBLER" THREAD CUTTER FOR SEWING MACHINES OR THELIKE Filed Sept. 17. 1950 l-I /8 1 ml!!!" I J I I c Patented Oct. 18,1932 CHARLES nnouBLER, or SPRINGFIELD, ivrrssounr THREAD CUTTER FORSEWINGMACHINES OR THE LIKE Application filed; September 17, 1930. SerialNo. 482,552.

The present invention relates to new and useful improvements in threadcutters for sewing machines or the like. i I

Thread cutters, such as have heretofore been used in connection withsewing machines, are customarily supported on the presser bar or thehead block of the machine and, being exposed,'are a menace to theoperators fingers if possessed of a suf'iciently keen edge to cut thethread effectively. The prior thread cutters are, therefore, usuallyprovided with edges that are so blunt that instead of cutting they breakthe thread pulled over them. Then too, after the threads have been cutor broken to release the sewed material from the machine, the two endsof the thread supply are .left loose and must be caught up and adjustedbelow the presser foot before a new seam is begun.

It is one of the objects of the present invention to overcome theseobjectionable features of prior devices of this character. rAnotherobject of the invention is to provide a thread cutter for sewingmachines or the like, which has a keen thread cutting portion so formedand positioned that the sharp cutting edge thereof cannot come incontact with the oper- A further object of the invention is to pro? videa thread cutter for sewing machinesor the like, which is formed andpositioned in such manner, that when the thread of a fin ished seam hasbeen severed from the material or goods, the two ends of the unusedthread may be yieldingly retained under the cutter bar in proper andconvenient position for the beginning of a new seam.

Still another object of the invention is to provide a thread cutterwhich is simple and compact in construction, and which is moreoverhighly efficientin operation. With the above and other objects in viewmy invention consists of the improved thread cutter for sewing machinesor the like, set forth in the specifications and in the claims annexedto and forming part of this specification.

. In the accompanying drawing, also forming part of this specification,I have illustrated two slightly varying: examples of actual embodimentsof my invention, constructed according to modes which I have thus fardevised for the practical application of the principles thereof, and inwhich: Fig. 1 is a front elevation of a special type of sewing machineequipped with the improved thread cutter; ,7

Fig. 2 is a top view of the front end of the same sewing machineshowing'the improved thread cutter in plate portion;

Fig. 3 isyan enlarged side view of the improved thread cutter detachedfrom the sewing machine; and. j

Fig. 4 is an enlarged top view of a slightly modified form of theinvention showing the same mounted upon a fragment of the bed plate of adifferent type of sewing machine from that shown in Figs. 1 and 2. 7

Referring to the drawing, the numeral 5 indicates the bed plate of asewing machine. Rising from the bed plate 5 at the rear end thereof isthe usual tubular arm 6, which terminates at the front in an integralhead 7. The head 7 has mounted therein for reciprocation, a needle bar 8of usual formation and a presser bar 9. The needle bar 8 carries aneedle 10 and the presser bar 9 has a presser foot 11. The needle bar isreciproc'able'by theusual mechanism (not shown) mounted, within the armwhereby stitches are formed in the material being sewed by the needle10, and a thread 12 cooperates during sewing with a lower thread 13supported in the bobbin member of a complemental loop taker(notshownlmounted below the sewing plate, to form the stitches.

To permit convenient access to the loop taker, a throat plate 14'covering ,a usual access opening,'is provided, this plate being pivotedto the bed plate 5 by a screw 15.

The bed plate 5 is formed flush with the top of the throat plate at theone side there of but is machined on the opposite side, as at 16,toprovide clearance for'swinging the throat plate on its pivot screw 15.In providing such clearance a shoulder 17 is formed running in astraight line from the back edge of the throat plate to the adjacentedge of the bed plate 5. There is also a narrow position on the bed slot19 provided in the bed plate, running transversely to and intersectingthe shoulder 17, this slot being cut to the same depth as the shoulder.The thread cutter 18 is formed with a downwardly directed hook portion18 and with a curved cutting portion 21 near its outer end, and also hasa lip C at the inner end thereof which is slightly long-er than thedepth of the slot 19 in which it is seated so that the front end of themedial portion of said thread cutter will, when positioned, standsomewhat above the surface of the bed plate to provide means, coactingwith the screw 20, for properly adjusting the frictional tension on thethreads which will lie between the bed plate and the flat, resilientrear end portion of the cutter bar adjacent the cutting edge thereof.

The thread cutter 18 is secured to the bed plate 5 and made adjustablethereto by the aforementioned screw 20. It is positioned upon said bedplate with the lip C seated in the slot19 and the inside edge of themedial portion thereof in direct line with the needle when viewed fromthe operative side of the machine; and when so positioned, and properlyadjusted as to tension, the cutting edge of said cutter will restclosely against the bed plate to protect said cutting edge and theoperators fingers from accidental injury.

The thread cutter is preferably formed of carbonized steel and issuitably tempered, first, to provide resiliency for the body portionthereof, and second, to insure an effective and keen cutting edge on thecurved cutting portion 21 when chamfered inwardly as shown at a toposition the cutting edge as close as possible to the bed plate.

It has now been made apparent that when a seam has been completed theoperator need only draw the two threads 12 and 13, which connect thefinished seam with the sewing machine, around and under the outside endof the thread cutter from the rear side thereof. By giving a slight pullthe threads will be readily severed and the two unused ends thereof willbe yieldingly retained under the resilient body of the cutter bar incorrect posi tion for beginning a new seam without further attentionand, furthermore, said thread ends will be long enough to tie or sew inwhen the seam has been finished. Moreover the thread ends are soretained, that when the new seam has been sewed a suflicient distance,the two yieldingly retained thread ends will be automatically drawn freefrom the thread cutter.

' It is to be understood that the gist of the present invention does notreside in any exact shape of the thread cutter but rather in its mode ofoperation and its disposition relative to the machine. The means bywhich the two thread ends are yieldingly retained after the threads havebeen cutloose from the material being sewed, is also an importantfeature of the present improvement.

Nor is the application of the present invention to be restricted to thetype of sewing machine illustrated and described. I have, therefore,illustrated in Fig. 4 a slightly modified form of the invention whereinthe thread cutter is mounted upon a fragment of the bed plate 5 of asewing machine which is not necessarily provided with a shoulder adaptedto be utilized in connection with the thread cutter previouslydescribed.

The improved thread cutter as illustrated in Fig. 4c is similar to theone already described, excepting that the hook portion 18 is eliminated,and a slight difference is introduced in the chamfer, shown at b. Thischamfer is, however, still formed to position the cutting edge at thebottom of the curved cutting portion of the thread cutter, close to thebed plate. 1

In this modification, as in the first described device the thread cutter18 is mounted flat upon the bed plate by the screw 20, the lip C restingin the slot 19, and the back edge of the thread cutter lying inapproximate alignment with the needle 10 when viewed from the operatingside of the sewing machine.

From the foregoing description, it will be noted that the inventionprovides a thread cutter especially adapted for use in connection withsewing machines or the like, which is simple and compact in constructionand which is moreover highly efficient in operation. The improved devicenot only insures maintenance of a keen cutting edge without danger toinquiring individuals handling the machine, but also maintains the cutends of threads in most effective condition for subsequent operation ofthe machine. The thread cutter is moreover out of the way of fabricbeing worked upon, and may be manufactured and applied to machines atbut slight cost.

It should be understood that it is not desired to limit the invention tothe exact details of construction herein shown and described, forvarious modifications within the scope of the claims may occur topersons skilled in the art.

What I claim as my invention is:

1. In combination with a thread utilizing machine having a presser foot,a thread cutter comprising a fiat resilient member secured to the frameof said machine entirely to the rear of the presser foot and having acutting edge disposed on the outer side edge of said member closelyadjacent to said frame. I

2. In combination with a sewing machine having a presser foot, a threadcutter for the needle and bobbin threads of said machine comprising aresilient member adjustably secured to the frame of saidmachine-entirely to the rear of the presser foot and having a cuttingedge disposed on the outer side edge of said member closely adjacent toand ap cutter comprising a resilient member adjustably secured to theframe of said machine entirely to the rear of said presser foot andhaving a cutting edge disposed on the outer side edge of said memberclosely adjacent to said frame, said member being formed to hold the endof a cut thread in proper position for subsequent operation of saidmachine.

4. In combination with a sewing machine having a presser foot, a threadcutter for the needle and bobbin threads of said machine comprising afiat resilient member secured to the frame of said machine entirely tothe rear of the presser foot of the machine and having a cutting edgedisposed on the outer side edge of said member approximately paralleland closely adjacent to said frame, said member being formed to hold theend of a cut thread in proper position for subsequent operation of saidmachine.

5. In combination with a sewing machine having a presser foot, a threadcutter for the needle and bobbinthreads of said machine comprising amember secured to the work supporting surface of said machinesubstantially in the plane of travel of the material operated upon bysaid machine and entirely to the rear of the presser foot of saidmachine, said member having a cuting edge disposed on the outer sideedge thereof approximatelyparallel and closely adjacent to said surface.

6. In combination with a thread utilizing machine having a presser footand a frame provided with a slot, a thread cutter positioned to the rearof the presser foot and comprising a member having a down turned frontend portion coacting with said slot and having a medial portion securedto said frame, the opposite rear end portion of said member beingprovided with a cutting edge disposed on the side edge of said memberclosely adjacent tosaid frame.

7. In combination with a thread utiliz-' ing machine having a presserfoot andv a frame provided with a slot, a thread cutter positioned tothe rear of the presser foot and comprising a member having a downturned front end portion coacting with said slot and having a medialportion secured to said frame, the opposite rear end portion of saidmember being resiliently biased toward said frame and having a cuttingedge disposed on the side edge thereof directly adjacent andapproximately parallel to said frame.

8. In combination with a sewing machine having a presser vfoot and aframe provided with a slot extending transversely of the direction oftravel of material past the needle thereof, a thread cutter positionedto the rear of the presser foot and comprising a member having a downturned front end-portion coacting with said slot and having a resilientopposite rear end portion extending away from said slot and from theneedle of said machine, said resilient rear end portion of said memberbeing provided with a cutting side edge disposed closely adjacent andapproximately parallel to said frame.

9. In combination with a sewing machine having a presser foot and a worksupporting surface provided with a slot, a thread cutter positioned tothe rear of the presser foot and comprising a member having a downturned front end portion coacting with said slot and having an oppositeresilient rear end portion extending away from said slot and from theneedle of said machine, said mem berextending away from said needle inthe direction of travel of material past said needle and having acutting edge at its rear outer side edge closely adjacent to saidsurface.

' 10. In combination with a sewing machine having a presser foot and awork supporting surface between the needle and the bobbin thereof, athread cutter for the needle and bobbin threads of said machinepositioned on the worksupporting surface entirely to the rear of thepresser foot and comprising a member having a resilient rear end portionadapted to receive saidthreads

